Do you really pixel sideways like that?
-his legs are too close together. Junksquashage.
-have the arms hang a bit more, he is heaps stiff.
-tried to put in elbows and knees
-his head was kind of pointy
-gave him a gut. your guy has basically no abdomen, it is just chest then wang, which is crazy.
Edit:
Fixed a bunch of weird problems I built into my earlier edit for some reason. (and the muscley version is basically in mimicry of ryona's, below).